000 AXNT20 KNHC 180005 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE JUL 17 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS... WEATHER OBSERVATIONS...AND RADAR. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...TROPICAL WAVES... TROPICAL WAVE ALONG 25W/26W EXTENDS THROUGH THE CAPE VERDE ISLANDS. A 1011 MB LOW IS ALONG THE WAVE AXIS NEAR 15N MOVING W NEAR 18 KT. THE LOW ITSELF CONSISTS OF WELL DEFINED TURNING IN THE STRATOCUMULUS FIELD. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS LIMITED TO THE INTERSECTION OF THE WAVE AXIS AND THE ITCZ GENERALLY FROM 8N-10N BETWEEN 25W-33W. TROPICAL WAVE IS ALONG 17N47W 4N50W. THE WAVE WAS ADJUSTED SLIGHTLY E EARLIER TO COINCIDE WITH THE MOST POLEWARD INFLECTION OF THE ITCZ...WHICH ALSO MESHES UP WELL WITH THE CREST OF HIGHER MOISTURE AS DENOTED BY THE UW-CIMSS SSMI DERIVED TOTAL PRECIPITABLE WATER PRODUCT. THIS WAVE PASSED DAKAR EARLY ON JULY 12 WHICH IMPLIES AN OVERALL WWD MOTION OF 6 DEGREES PER DAY...OR 15 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 150 NM EITHER SIDE OF THE AXIS FROM 6N-10N. THE WAVE MAY ALSO BE ENHANCING THE CONVECTION ALONG THE ITCZ FURTHER W AS DESCRIBED BELOW. TROPICAL WAVE IS OVER THE CARIBBEAN ALONG 77W S OF 20N MOVING W 15-20 KT. THIS WAVE MAY NEED TO BE ADJUSTED FURTHER W ON THE 0000 UTC ANALYSIS AS A WWD MOVING SURGE OF SHOWERS AND TSTMS HAS PUSHED TO THE COAST OF NICARAGUA AND HONDURAS. THE WAVE REMAINS EMBEDDED IN FAIRLY STRONG 850-700 MB FLOW AND THUS THE MOVEMENT OF THE WAVE MAY BE UNDERESTIMATED. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N16W 10N24W 7N37W 12N46W 7N58W. EXCEPT FOR THE CONVECTION DESCRIBED IN ASSOCIATION WITH THE WAVE ALONG 26W...SCATTERED MODERATE TO STRONG...POSSIBLY ENHANCED BY AN APPROACHING TROPICAL WAVE ALONG 17N47W 4N50W IS GENERALLY WITHIN 60-90 NM EITHER SIDE OF A LINE FROM 11N60W 13N52W. ...DISCUSSION... GULF OF MEXICO... THE ACTIVE WEATHER WHICH WAS PRESENT IN THE WESTERN GULF OF MEXICO OFF THE TEXAS/MEXICO COAST HAS DIMINISHED CONSIDERABLY WITH ONLY ISOLATED MODERATE TO STRONG CONVECTION NOTED JUST OFF THE LOUISIANA COAST. REMNANT MID TO UPPER LEVEL CLOUD DEBRIS REMAINS OVER THE GULF WEST OF 92W. WATER VAPOR IMAGERY SHOWS MID TO UPPER LEVEL MOISTURE BEING ADVECTED FROM THE WESTERN GULF INTO THE DEEP SOUTH AND TENNESSEE RIVER VALLEY IN MODERATE UPPER LEVEL SW FLOW...AND TO THE E/SE S OF 23N AROUND THE EASTERN PERIPHERY OF AN ANTICYCLONE OVER THE EAST PACIFIC NEAR 17N105W. ELSEWHERE...A SMALL AREA OF SCATTERED SHOWERS/TSTMS WERE MOVING OFF THE YUCATAN COAST INTO THE BAY OF CAMPECHE AND ALSO THE WEST COAST OF FLORIDA. ON THE LARGE SCALE AT THE SFC...THE WRN PORTION OF AN ATLC SFC RIDGE CONTINUES TO DOMINATE AND IS GENERALLY EXPECTED TO PERSIST OVER THE NEXT COUPLE OF DAYS. CARIBBEAN SEA... SCATTERED SHOWERS/TSTMS ARE MOVING UNTO THE COAST OF NICARAGUA AND HONDURAS AND NOTED ELSEWHERE OVER THE WRN CARIBBEAN WEST OF 80W AND SOUTH OF 15N. THIS ACTIVITY IS BEING SUPPORTED BY UPPER DIFFLUENCE SW OF AN UPPER LOW BETWEEN JAMAICA AND ERN CUBA AND LOW LEVEL SPEED CONVERGENCE. FURTHER UPPER DIFFLUENCE BETWEEN THE UPPER LOW AND UPPER RIDGING OVER THE ERN CARIBBEAN WAS RESPONSIBLE FOR SOME MODERATE CONVECTION NOTED NEAR PUERTO RICO EARLIER. THIS CONVECTION HAS SINCE DIMINISHED. OTHERWISE MODERATE TO FRESH TRADES ARE IN PLACE ON THE SW PORTION OF AN ATLC SFC RIDGE AND EXPECTED TO PERSIST OVER THE NEXT COUPLE OF DAYS. UW-CIMSS SAHARAN AIR LAYER PRODUCT DEPICTS FAIRLY DENSE REGION OF AFRICAN DUST SWEEPING WESTWARD OVER THE EAST-CENTRAL CARIBBEAN. HAZE AND OTHER VISIBILITY RESTRICTIONS WERE REPORTED AT DOMINICA...MARTINIQUE AND ANTIGUA. ATLANTIC OCEAN... ISOLATED TSTMS ARE OVER THE FAR WRN ATLC W OF 77W UNDERNEATH AN UPPER HIGH. OVERALL THOUGH SFC RIDGING DOMINATES SW OF A 1030 MB HIGH PRES CENTER NEAR 36N50W. INVERTED SFC TROUGHING EMBEDDED IN THIS RIDGE IS ALONG 29N61W 25N61W 20N67W. THIS...ALONG WITH LIFT AHEAD OF THE MID TO UPPER LOW NEAR 29N64W...IS SUPPORTING SCATTERED SHOWERS/ISOLATED TSTMS N OF 20N BETWEEN 56W-63W. THE AREA N OF 18N AND E OF 55W IS WIDELY DOMINATED BY FAIR WEATHER...SCATTERED LOW TO MID CLOUDS AND MODERATE TRADES. AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 17N55W DOMINATED THE TROPICAL ATLANTIC WEST OF 40W WITH ANOTHER UPPER RIDGE OVER THE FAR ERN ATLC IN BETWEEN IS A WEAK UPPER TROUGH N OF 18N BETWEEN 35W-45W. DENSE AREA OF AFRICAN DUST NOTED OVER MUCH OF THE AREA E OF 40W. $$ COBB